Bonsai tree

This Trident maple root-over-rock is from Bonsai Today issue 24 (a special issue devoted to rock planting).
Root-over-rock is where the roots grow over the rock and down into soil below. Root-on-rock is where the roots grow in a soil pocket (or soil pockets) in the rock (see below).

A Black pine bonsai in the root-on-rock style. The way the tree is growing to the right serves to balance the part of the rock that thrusts out to the left. However, we have been buying back rare old out-of-print issues for sometime and are now offering them on Stone Lantern.

A small Trident maple with its roots growing over a small rock.

A Japanese white pine bonsai in the root-on-rock style that brings to mind an island in the ocean or in a lake. Much like the Black pine above, the right leaning tree is balanced by the bulk of the rock on the left.

Source: Bonsai Bark